Wiznet chip SPI speed

[B00mb0x]

I am trying to connect a Wiznet W5500 shield to an ESP32-S3 board using jumper wires for prototyping. I followed the instructions in #11474 and compiled and uploaded a custom firmware. I used the code by @robert-hh from #12820 in order to evaluate if the code is working. Unfortunately lan.isconnected() never returns true. I tried using micropython version 1.22 and 1.23 with similar outcomes.

When looking at the SPI clock with an oscilloscope I can see a 40MHz signal roughly once every second, however the SPI baudrate is only set to 500kHz and when I try using spi.write() for debugging it runs on 500kHz. I even added #define MICROPY_HW_WIZNET_SPI_BAUDRATE (500000) in mpconfigboard.h with no effect.
Is there a way to slow down the baudrate of the network library? 40MHz is too fast for my jumper wire setup.

mpconfigboard.cmake:

set(IDF_TARGET esp32s3)

set(SDKCONFIG_DEFAULTS
    boards/sdkconfig.base
    boards/sdkconfig.usb
    boards/sdkconfig.ble
    boards/sdkconfig.spiram_sx
    boards/SIPLOG_ESP32_S3/sdkconfig.board
)

if(MICROPY_BOARD_VARIANT STREQUAL "SPIRAM_OCT")
    set(SDKCONFIG_DEFAULTS
        ${SDKCONFIG_DEFAULTS}
        boards/sdkconfig.240mhz
        boards/sdkconfig.spiram_oct
    )

    list(APPEND MICROPY_DEF_BOARD
        MICROPY_HW_BOARD_NAME="Generic ESP32S3 module with Octal-SPIRAM"
    )
endif()

mpconfigboard.h:

#ifndef MICROPY_HW_BOARD_NAME
// Can be set by mpconfigboard.cmake.
#define MICROPY_HW_BOARD_NAME               "SIPLOG ESP32-S3 BR500k"
#endif
#define MICROPY_HW_MCU_NAME                 "ESP32S3"

// Enable UART REPL for modules that have an external USB-UART and don't use native USB.
#define MICROPY_HW_ENABLE_UART_REPL         (1)

#define MICROPY_HW_I2C0_SCL                 (9)
#define MICROPY_HW_I2C0_SDA                 (8)

//SPI issues
#define MICROPY_HW_WIZNET_SPI_BAUDRATE  (500000)

sdkconfig.board:

CONFIG_ESPTOOLPY_FLASHMODE_QIO=y
CONFIG_ESPTOOLPY_FLASHFREQ_80M=y
CONFIG_ESPTOOLPY_AFTER_NORESET=y

CONFIG_ESPTOOLPY_FLASHSIZE_4MB=
CONFIG_ESPTOOLPY_FLASHSIZE_8MB=y
CONFIG_ESPTOOLPY_FLASHSIZE_16MB=
CONFIG_PARTITION_TABLE_CUSTOM=y
CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions-8MiB.csv"

CONFIG_COMPILER_OPTIMIZATION_SIZE=y
CONFIG_ETH_USE_SPI_ETHERNET=y
CONFIG_ETH_SPI_ETHERNET_W5500=y

main.py:

from machine import Pin, SPI
import network
import socket
import utime

sck = Pin(12)
mosi = Pin(11)
miso = Pin(13)
cs = Pin(14, mode=Pin.OUT, value=1)
rst = Pin(7)

spi = SPI(2,baudrate=500,sck=sck,mosi=mosi,miso=miso)
#spi = SoftSPI(baudrate=500000,sck=sck,mosi=mosi,miso=miso)

lan = network.LAN(phy_type=network.PHY_W5500, phy_addr=1,spi=spi,cs=cs,int=rst, ref_clk_mode = Pin.OUT)
lan.active(True)
while not lan.isconnected():
    print(".", end="")
    utime.sleep(0.25)

[robert-hh]

Looking at the schematics, the W5500 INT signal is not connected to the board pins. The signal that is connected is RST (Reset), which should be kept high and pulled low for reset. So you have to configure reset=rst, and not int=rst. refclk_mode and phy_addr may both be not applicable, but do not harm.

[glenn20]

And re. the soft resets, if you put a nic.active(0) in your init script, it connects just fine after a soft reset, eg. (adapted from Robert's example code):

import time
import machine
import network

SPI_PINS = dict(sck=10, miso=11, mosi=12)
LAN_PINS = dict(cs=9, int=13, reset=14)
IFCONFIG = ("192.168.10.99", "255.255.255.0", "192.168.10.1", "192.168.10.1")

spi = machine.SPI(1, **SPI_PINS)
lan = network.LAN(phy_type=network.PHY_W5500, spi=spi, phy_addr=1, **LAN_PINS)

# Ensure lan is inactive after a soft reset (will throw OSError if after hard reset)
if machine.reset_cause() == machine.SOFT_RESET:
    lan.active(0)  # Ensure off after soft reset
lan.ifconfig(IFCONFIG)

def connect(lan):
    lan.active(1)
    while not lan.isconnected():
        print(".", end="")
        time.sleep(0.25)
    print()
    print(f"Connected on {lan.ifconfig()[0]}")

connect(lan)

[glenn20]

Using lan.config(mac=b'\x02\x04\x04\x12\x34\x56') after lan instantiation and before lan.active() worked on my S3 board.

Thanks for the tip. The esp32s3 (and other esp32 devices) reserve 4 sequential mac addresses for use by the device. The fourth one is reserved for the LAN. See https://docs.espressif.com/projects/esp-idf/en/v4.4/esp32s3/api-reference/system/system.html#mac-address.

machine.unique_id() will return the base mac address (without having to startup the wifi interfaces).

So, I now use:

mac = bytearray(machine.unique_id())
mac[-1] += 3  # Add 3 to last octet of base mac to get lan mac
lan.config(mac=mac)

[glenn20]

Turns out that dhcp servers seem to ignore requests from mac address: b\x00\x00\x00\x00\x00\x00 ;-)

[robert-hh]

Thanks. That's a good hint.

[glenn20]

I have submitted PR #15385 to stop lan.active(True/False) raising OSError if the lan is already in the desired state.

[B00mb0x]

I have ordered two new W5500 development boards: the ETH Wiz click and the W5500 Lite board. For some reason, the Arduino shield and the ETH Wiz click still don't work properly. However the W5500 board works using the same code. Thanks for all the help!

[liudr]

I know you've found your solution but do you feel like you owe the helpers a clear answer whether the "int=rst" was the source of your error, not the different boards or any steps in #11474?

[B00mb0x]

I cannot say for sure what the error was. All I can say is, that it now works with the W5500 Lite board, but not with the Wiz click board and also not with the Arduino MKR shield. I guess it's not related to the int=rst thing, as the click board also has an interrupt pin, but still doesn't work. My guess is, that is has something to do with the pmode resistors. However I cannot confirm this theory, as I can't find the schematic for the W5500 Lite board.

[liudr]

Doing the int=rst is simply wrong! Maybe you happened upon a pin configuration on the "working" board where your defined "rst" variable was indeed containing the pin number connected to W5500's int pin on the "working" board (pin 7?) or just wired Ethernet's int pin to your ESP32 pin 7 by sheer chance. Hopefully later people will read this post carefully instead of glancing at part of this post and just conclude that the click board or Arduino shield doesn't work.

[B00mb0x]

I see, sorry I didn't describe my solution detailed enough. I used int=rst because the Arduino board doesn't have the int pin. As discussed in a previous answer, I had to define the int pin, but on the physical wiring I disconnected it, so basically int was connected to nothing.
With the two newer boards I failed to mention, that I connected the int pin of the board to the according GPIO on the ESP32.